analytic polyhedron

Definition.

Suppose $G\subset {ℂ}^n$ is a domain and let $W\subset G$ be an open set. Let $f_1,\mathrm{\dots },f_k:W\to ℂ$ be holomorphic functions. Then if the set

is relatively compact in $W$, we say that $\mathrm{\Omega }$ is an analytic polyhedron in $G$. Sometimes it is denoted $\mathrm{\Omega }(f_1,\mathrm{\dots },f_k)$. Further $(W,f_1,\mathrm{\dots },f_k)$ is called the of the analytic polyhedron.

An analytic polyhedron is automatically a domain of holomorphy by using the functions that define it as $g(z):=\frac{1}{e^{i\theta }-f_j(z)}$ to show that $g$ cannot be extended beyond a point where $f_j(z)=e^{i\theta }$. Every boundary point of $\mathrm{\Omega }$ is of that form for some $f_j$.

Furthermore every domain of holomorphy can be exhausted by analytic polyhedra (that is, every compact subset is contained in an analytic polyhedron) and in fact only domains of holomorphy can be exhausted by analytic polyhedra, see the Behnke-Stein theorem.

Note that sometimes $W$ is required to be homeomorphic to the unit ball.

Title	analytic polyhedron
Canonical name	AnalyticPolyhedron
Date of creation	2013-03-22 14:32:39
Last modified on	2013-03-22 14:32:39
Owner	jirka (4157)
Last modified by	jirka (4157)
Numerical id	7
Author	jirka (4157)
Entry type	Definition
Classification	msc 32T05
Classification	msc 32A07
Synonym	analytic polyhedra
Defines	frame of an analytic polyhedron